Research is being done on the preparation of porcelains from new raw materials. Attempts are being made by the control of particle size to reduce firing shrinkage and to increase dental porcelain strength. Fillers for dental composite resins are being developed from microporous glasses prepared by the gel route. BIBLIOGRAPHIC REFERENCE: Mabie, C. P. Evaluation of the Physical Properties of Crown Dental Porcelain and the Effect of Newly Developed Anti-Balling Additive. J. Biomed. Mater. Res. 9:1-25 (1975).